Method of making stems for electric lamps



S p 1949- E. MICKLEY 2,482,119

METHOD OF MAKING STEMS FOR ELECTRIC LAMPS Filed Dec. 15, 1941 Ihveencor;dxj/ Eric-h Mickleg,

@ His Afiovneg.

Patented Sept. 2c, 1949 r 2,482,119

METHOD OF MAKING STEMS FOR ELECTRIC LAMPS T Erich .Mickley,Berlin-Zehlendorf, Germany;

vested in'the Attorney General of the United S ates.

Application December 15, 1941, Serial No. 423,106 In Germany Oc'tober8,1940 Section 1, Public Law 690; August 8, 1946 Patent expires October 8,1960 2 Claims. (Cl.49 78)'- 1 2 My invention. relates to a method ofmaking ness, and leading the band between the co-perat seals betweenglass and metal members, and more 'ing punch and die members of apunching" tool, particularly to the manufactureof stems for eleconemember of which is equipped with 'a multitric lamps, discharge tubes orsimilar devices, pliciy of leading-in wires protruding therefrom, suchstems comprising a glass'disc having lead- 5 after which the punchmember is actuated soas ing-in conductors sealed therethrough. to puncha glass blank or dish out of the glass The bulbs or envelopes ofelectric lamps, disband. At the same time, the leading-in wires chargetubes and similar devices are frequently protruding-from the punchmember are forced closed by means of stems comprising fiat glass throughthe glass mass of the disc'and are firmly sealing discs which are fusedto the edge of the embedded in the latter. glass lamp bulb or. envelope.and which carry a If the glass blank or disc is to consistof hardmultiplicity of leading-inwires. Sofar, such stems glass, that is tosay,a glass which can withstand have been usually produced by firstpressing, from very high temperatures and which has a low coglass, aplate-shaped disc .with a multiplicity'of eflicient of thermalexpansion, then it is advisholes for the leading-in wires, and theninserting r able to cover, prior to the closin of the punch and sealinthe leading-inwires into the holes of and die members, the leading-inwiresprotrudthe glass disc, if necessary with the help of a ing from thepunch member with a glass layer,

. compensating sealing glass of lower meltin point. especially onthoseportions of the leading-in wires It is also vknown to position theleading-in wires which are to lie within the glass mass of the disc; ina predetermined position within a mold, and to and the coefficient ofthermal expansion of such then force liquid or softened glass around theglass layer must lie between the coeflicient of leads So that this glassconstitutes the sealing disc. thermal expansion of the glass out ofwhich the Both of the above described methods of producing sealing discis made and the coefiicientof thermal stems are comparatively slow anddo not always expansion of the metal of which the leading-in permit asufficiently tight embedding of the leadwires consist.

ing-in wires in the glass disc. Referring to the drawing, in front'of anoutlet One object of my invention is to providean imopening I n an O 2 wc y be heated in proved. method of producing stems for electric anydesired manner, is mounted a pair of rolls lamps, discharge tubesandsimilar devices which 3 through which passes a glass rod 4 which runs issimpler and more rapid than methods hereto continuously through the ovenand is'heated fore used and which enables a more economical therein to asofteningtem'perature; The'indiviproduction of such stems. dual rolls'ofthe system ofrolls 3 are so adjusted A feature of the invention is thepunching of a with respect o'each' other t a the glass od 4 glass discfrom a ribbon of .plastic glass, and the is rolled into a lass bandorribbon 5 of the thicki-nsertion and embeddin of the leading-in wiresness of the sealing d c w h is 130108 p 'fl into said discsimultaneously with the punching The glass band 5 resu t ng m theIOIIiIIgDI'OCBSS thereof. is held in a horizontal position bysupportingposts Further objects and advantages of my inven- 6 Which'a e 'equipp 'wth r n plates 1 0 ption will appear from the following description ofporting rollers. The'glass band 5 is led through a species thereof andfrom the accompanying 40. a press and pun h' l which onsists of astaschematic drawin in hich; tionary diemember 8 and a movable upperpunch Fig. 1 is an elevation of apparatus for practicmembe 9 ar n d tove Ve a ly a to ingthe method comprising my invention; Fig. 2 closeagainst'the' die member 8. Between the I is a top view of modifiedapparatus comprising members '8, T9 and the pair of rolls 3, set'of asingle die and. a plurality of cooperatingpunches burners l0 may beprovided for the purposeof carried by a turret; and Fig.3 is a sectionalview rehe'atingthe glass band 5 which is cooled during of a stemproduced by the method according to l the rolling process. In thismanner the band 5 the invention and including an exhaust tube 1, of glasw ll have thenecessalvsoftninstemsealed thereto; and Fig. 4 is anelevation of. a perature for the molding thereof. lead-in wirepreliminarily coated with glassprior. i The upper movable punch member'9 ofthe to manufacture of the stem. punching tool has a recess H in itsunder or In accordance with the invention, the stems punching surfacewhich corresponds to the shape may be produced by heatin a glass roduntil of the sealing member or disc to be produced. it is soft, thenrolling the softened glass rod into A multiplicity of verticallyextending holes i2 is I aband or ribbon of the desired disc or platethick-v 'provided in the body portion of the movable punch member 9above the recess ll therein, through which holes the leading-in wires l3extend and are'so clamped thereinas.to protrude freely downward: beyondthe under surface 14 of the movable punch member 9. The leading-in wires13 may be cut to the desired length and, inserted in the upper movablepunch member 9 of the punching tool.

bers, for instance, spring actuated bolts l5,"are provided on the uppermovablepunchime'mb'erj for the purpose of securing the leading-irr-wires|2 in the said movable a recess l6 which,

flcalfalignment with the holes |2in the upper .punch'rnember 9. Theuppermost ends of the holesl'l arepreferably countersunk, as indicatedat. 19 in Fig. l, to provide upwardly flaring eniiarged recesses in thebottom surface of the recess It.

When the punching toolis closed, the edge or [rim 20 of the uppermovable punch'member 9 punches from the glass band which lies betweenthe cooperating punch and die members, a plate shapeddisc orjglasstheleading-in wires l3 protruding V punch member9 penetrate throughthesoft glass mass of the band 5 and enter the holes II in the die member8. The free ends of the leading-in wires l3 protruding v '-.,ber 9; arethus received within the holesfl'l, the said holes !'I beingmade ofslightly larger diam- -ete r thanthat of the leading-in wires so as to 1permit free entry of the leading-in wires thereinto. In passing throughthe plastic glass band or ribbon 5,,the leading-in wires l3 carry acerf-tain amount of the plastic glass along therewith and into thecountersunk recesses IQ of the'holes H where it is formed into the shapeof the said countersunk recesses by the compression ofthe shaped seal"punching-tool to thereby form conical reinforcing extensions or nipples29 (Fig. 3) on the sealing disc 28. During the punching operation, theclamping members I5, whichsecure the leading-in wires. [3 in the upperpunch are released, an operation whichmay atthe lastmoment when themoldv or punching tool is closed and which may be accomplished by alimiting or stopping device. When the clamping members l5are so 7 member9 is then moved. upwardly and returned to its normal starting orinoperative position. During the upward or return movement or the .upperpunch member 9, theleading-in wires l3 remain in the punched glass discwhereupon they, 5

Inthe center part o f the punched sealing disc 29 '(Fig. 3) produced asdescribed her'einabove,

become hermetically sealed within theglass mass -of the disc .while thelatter is gradually-cooling. In order to eliminate the insertion oftheleading-in wires l3 after each upward ,movement of the upper punchmember 9, a number of spools,

.. or coils 2i; of wire corresponding to the desi d' 70""edge' of suchhole. It is .ihe le a th e his punched 'out. Alternatively; the exhausttube [number of leading-in wires may be arranged above the upper punchmember 9 of the punch- ,ing tool. From these spools of Wire, a corre-,sponding nu ber of wire sections 22, all ofeigactly the same size andlength, can

from the upper punch memmember 9, take place" released, the upper punch,'60

- in wires in the sealing disc.

be rolled or fed off Suitable clamping, mems of thepunching toolhas;its}

a punch member 9;'or

and can be introduced positively into the holes l2 of the upper punchmember, for instance, by means of; tworollers 23, 24 which grasp thewire elastically between themselves and which may be moved by means of aratchet wheel (not shown). After the wire sections 22 have been reeledoff the wire spools -21.. and have been introduced in the holes; l2 inthe upper punch member 9, the ends of such wire sections may be cut off,by means 25, closely above the upper they may be out immediately 26which project upwardly 9 and through of a coacting knife adjacent the'nozzles from. the upper .punch member which the wires 22 enter.

As indicated in Fig". 2,

the die member 8 of the punching-tool may co-operate alternately withseveral upper punch members 9 instead of with only one upper punchmember, and these upper punch members 9 can then be mounted on a supportvor turret 21 which is rotated intermittently.

' It then becomes possible to introduce wires 22 "in other upper punchmembers 9, to out these wires 22'to. the desired length to'form theleadingin wires [9; and to check up the relation of the variousparts of'the upper 'punch member, all this during" the'time when a'stemisproduced by the actuation .of that movable punch member I 9 which is inco-operatingpunching relation with the die member 8.

'In those cases where the embedding of the ,l'eacling in wires l3 in thesolidified glass body or disc proves to be unsatisfactory (this mighteasily J occur when the glass body, and at the same time, f from theupper '35 be swung away in I V I discs are made of hard glass), theupper punch members 9 of the punching tool'are preierably so designedthat theycan order that, in one operating Y position of theintermittently rotating supports f forthe upper punch members '9, thecorresponding upperpunch'me'mber 9 may be swung up so as to becomeinverted, thus permitting the placing of glass rings (not shown) on thethen upwardly protruding leading-in wires l3. The co- 'efficient ofthermal expansion of I the said glass ,rings should, of course, liebetween the sealing discs are to be made and that of the rnetal out oiwhich the leading-in wires l3' are L made. In the saidoperati'ngposition, "rings, are fused'bymeans of suitable burners in tires l3within the recess 3 glass layer 13f which,'later '-'of'the punching tooland the glass such a way that the portions of the leading-in i U H inthe upper punch member Will beprovided with a strongly adhering theinsertion of the "leading-in'lwires into the glass band 5, will liewithin the glass mass of the said band. Such glass rings thus form anintermediate coating between the metal of 'theleading-in wires [3 and te a m n W the final shape of th thegiass' of the sealing disc, whichcoating guarantees a vacuum tight embedding of the'leading- The number.of leading-in wires to be inserted, ith respect to one another, and

e punched glass stem all may. of course, be optional.

a 11011: 39lm'ay be subsequently formed, by means heating an eirhaust tuthe coeflicient or thermal expansion of the hard glass of which on,during the closing the hole resulting from the expansion of the heatedair trapped within the closed exhaust tube out through the plastic glassat the center of the disc.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. The method of making stems for electric lamps and similar deviceswhich comprises preliminarily fusing a coating of glass on intermediateportions of a plurality of lead-in wires, forming plastic glass into aribbon and then forming stems from successive portions of the ribbon bypunching blanks therefrom and simultaneously inserting the lead-in wiresthrough the blanks to embed the coated portions thereof in the said 15blanks.

2. The method of making stems for electric lamps and similar deviceswhich comprises preliminarily fusing a coating of glass on intermediateportions heating a rod of glass to a. plastic condition and compressingit into a ribbon and then forming stems from successive portions of theribbon by punching blanks therefrom and simultaneously of a plurality oflead-in wires,

blanks.

ERICH MICKLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 314,828 Haines Mar. 31, 1885333,028 Stanley Dec. 22, 1885 805,963 Jackson Nov. 28, 1905 1,770,335Fuwa July 8, 1930 1,831,144 Shearer Nov. 10, 1931 2,030,186 Rose Feb.11, 1936 2,114,869 B0] et al Apr. 19, 1938 2,277,150 Scharfnagel Mar.24, 1942 FOREIGN PATENTS Number Country Date 720,083 Germany Apr. 23,1942

